The present invention relates to a light emitting diode (LED) display, particularly an improved frame for light emitting diode display.
Conventionally, LED displays are substantially classified into two types according to the frames used for LED chips--Lead Frame and P.C.B. (printed circuit board) Frame. The former is rarely used because of its high assembly cost and it is difficult to obtain a satisfactory matching on LED's intensity and color. The latter is widely used because its cost is low, its production is easy, and it is easy to match intensity and color.
As shown in FIG. 4, the LED display with a printed circuit board (10) as a base uses a reflector (11) to reflect upward and converge light emitted from every LED chip (12) to increase intensity. However, as one of the characteristics of the LED chip, a part of the light emitted (A) is emitting upward, while the other part of the light emitted (B) is emitted to the surroundings, as shown in FIG. 5. Upon reflection of the light emitted to the surroundings at the reflective surface (14) on the reflector (11), the intensity (i) of the upward reflected light is inversely proportional to the square of the distance (d2) between the reflective surface (14) and the LED chip (12). Then, if d1&lt;d2, i1&gt;i2. In other words, the smaller the distance between the reflective surface (14) and the LED chip (12), the greater the intensity of the reflected light. However, the conventional reflector (11) has to surround the LED chip (12) and the wire bonding position (13) so that a considerable large distance between the LED chip (12) and the reflective surface (14) is required. Then, it is hard to converge the light reflected from the reflective surface (14), there is a loss on intensity, and the conventional LED display is not satisfactory.